If you have a lathe , make a double diameter pushing piece ( drilled through centre for 1/2" + clearance) that fits the bore of the bush and the bore of the SA, mine drew in with a 1/2 " screwed rod through the middle and some nuts to squeeze it together.
Make sure the bore of the SA is shiny bright, de burred and check ID matches Bush OD. A whizz with some 100 grit wrapped round a stick in a power drill will help clean the SA bore .